Recently, silicon carbide has been used in various electronic devices as a semi-conductor material for various purposes. In particular, the silicon carbide is very useful because the silicon carbide has the superior physical strength and high resistance against the chemical attack. In addition, the silicon carbide represents the superior electronic characteristics, such as the high radiation hardness, relatively wide bandgap, high saturated electron drift velocity, high operating temperature, and high absorption and emission of quantum energy in the blue, violet and ultraviolet bands of a spectrum.
Silicon carbide powders can be prepared by mixing and heating source materials, such as a silicon source and a carbon source. In order to prepare the silicon carbide powders, an Acheson scheme, a carbon-thermal reduction scheme, a liquid polymer thermal decomposition scheme, and a CVD (Chemical Vapor Deposition) scheme have been generally known to those skilled in the art. In particular, the liquid polymer thermal decomposition scheme or the carbon-thermal reduction scheme is used to synthesize high purity silicon carbide powders.
In general, to prepare silicon carbide sinter through a hot press scheme, silicon carbide powders having a grain size in the range of 0.5 μm and 5 μm are used. In addition, to prepare silicon carbide sinter or grow the single silicon carbide crystal through a reaction sintering scheme, silicon carbide powders having the grain size of 10 μm or more are required.
However, the silicon carbide powders prepared through the above scheme have many difficulties in controlling the grain size thereof. Particularly, to make the grain size beyond the range of 0.5 μm to 5 μm, the silicon carbide powders prepared through the above scheme actually have limitation.
Therefore, a scheme of preparing silicon carbide powders having the grain size of 10 μm or more is required.